1 Land contracts or contracts for deed are a security agreement between a seller, called a Vendor, and a buyer, called a Vendee.  The Vendor agrees to sell a property by financing the purchase for the Vendee.
The two DNA strands are held together by interchain hydrogen bonds. H-bonds pair the bases in one chain to the complementary bases in the other chain. (A/T and G/C).
A nucleotide is held together by covalent bonding. The two strands of DNA are held together by hydrogen bonds between the complimentary base pairs.